MOSSBERG 590RM | 12ga | 18.5″ Barrel | 10+1 | MFG# 50213

The Mossberg 590RM is a 12-gauge, pump-action shotgun built around a detachable double-stack magazine to provide higher capacity in a compact platform. It pairs an 18.5-inch barrel with an integrated heat shield, a Picatinny top rail and Magpul MBUS 3 flip-up sights. The rifle-style ergonomics include a 5-position adjustable synthetic stock with a Magpul MOE pistol grip and an ambidextrous rotary safety selector.

Purpose-built for security roles and professional or civilian range training, the 590RM emphasizes magazine-fed capacity and modular accessory mounting without departing from a time-tested pump-action core.

Product Specifications

• The model is 590RM.
• The manufacturer is Mossberg.
• The gauge is 12 Gauge.
• The action type is Pump-Action.
• The barrel measures 18.5 inches.
• The chamber accepts 2.75 inch shells.
• The capacity is listed as 10 + 1.
• The product includes 1 x 10-round detachable magazine.
• The stock is a 5-position adjustable synthetic stock in black with a Magpul MOE pistol grip.
• The sights are Magpul MBUS 3 adjustable flip-up sights.
• The receiver is aircraft-grade aluminum.
• The barrel features an integrated heat shield.
• The choke type is Accu-Choke with a cylinder bore installed.
• The magazine type is detachable.
• The UPC is 015813502139.

Compact, modular and purpose-built, the 590RM blends a familiar pump-action manual with a detachable double-stack magazine and modern furniture to suit users who need higher capacity and accessory flexibility. The top Picatinny rail and adjustable stock make it straightforward to configure for optics, lights or other mission-specific gear while the integrated heat shield and rugged synthetic furniture support extended use at the range or in professional security contexts.

Owners and reviewers commonly note the platform’s durable construction and the practical capacity advantage of the magazine-fed design.